The present invention relates to a sealing means for a thermostat mounted on a motor vehicle, and more particularly to a tubular sealing member which can be automatically deformed in the form of a bellows when the tubular member is contracted.
The wax-pellet thermostat is used in a cooling system of the motor vehicle. When coolant temperature in the cooling system rises above a predetermined temperature, a valve in the thermostat opens to pass the coolant to a radiator, thereby lowering the temperature of the coolant. The valve is closed when the temperature drops. Consequently, a guide member mounting the valve reciprocates along a rod. In order to seal a sliding portion of the guide member, a dynamic seal such as a packing is provided. However, a conventional seal is liable to be deteriorated because of severe circumstances. More particularly, the coolant includes fine molding sands, fine particles of rusted iron, oil and other particles which form a sludge with antifreeze mixture.